PannerNode.positionZ

The positionZ property of the PannerNode interface specifies the Z coordinate of the audio source's position in 3D Cartesian coordinates. The complete vector is defined by the position of the audio source, given as (positionX, positionY, positionZ), and the orientation of the audio source (that is, the direction in which it's facing), given as (orientationX, orientationY, orientationZ).

Depending on the directionality of the sound (as specified using the attributes coneInnerAngle, coneOuterAngle, and codeOuterGain), the orientation of the sound may alter the perceived volume of the sound as it's being played. If the sound is pointing toward the listener, it will be louder than if the sound is pointed away from the listener.

The AudioParam contained by this property is read only; however, you can still change the value of the parameter by assigning a new value to its AudioParam.value property.

Syntax

Value

An AudioParam whose value is the Z coordinate of the audio source's position, in 3D Cartesian coordinates.

Example

In the following example, you can see an example of how the createPanner() method, AudioListener and PannerNode would be used to control audio spatialisation. Generally you will define the position in 3D space that your audio listener and panner (source) occupy initially, and then update the position of one or both of these as the application is used. You might be moving a character around inside a game world for example, and wanting delivery of audio to change realistically as your character moves closer to or further away from a music player such as a stereo. In the example you can see this being controlled by the functions moveRight(), moveLeft(), etc., which set new values for the panner position via the PositionPanner() function.

To see a complete implementation, check out our panner-node example (view the source code) — this demo transports you to the 2.5D "Room of metal", where you can play a track on a boom box and then walk around the boom box to see how the sound changes!

In terms of working out what position values to apply to the listener and panner, to make the sound appropriate to what the visuals are doing on screen, there is quite a bit of fiddly math involved, but you will soon get used to it with a bit of experimentation.